Cam box for knitting machine

ABSTRACT

A knitting machine cam box construction defines a cam track having upper and lower surfaces and through which the butts of knitting needle-actuating jacks pass. Said construction comprises a first cam means defining an upper surface of the cam track and a second cam means defining the lower surface of the cam track. Said second cam means includes a tuck cam and an up-throw cam located adjacent each other. The second cam means also includes a follower cam and means mounting the follower cam for adjusting movement with and in response to adjusting movement of the tuck cam. Moreover, means is provided for simultaneously adjusting the position of the up-throw cam and the stitch cam relative to the tuck cam.

United States Patent 1191 Paepke Jan. 9, 1973 [54] CAM BOX FOR KNITTING MACHINE FOREIGN PATENTS OR APPLICATIONS 1 1 lnvemorl g p Rottenburg am 1,133,066 11 1968 Great Britain ..66/57 ec ar, ermany [73] Assignee: The Warner & Swasey Company, Primary Examiner-Ronald Feldbaum Cleveland, Ohio Attorney-Yount and Tarolli [22], F1led: Nov. 2, 1970 [57] ABSTRACT [2]] Appl' 86059 A knitting machine cam box construction defines a cam track having upper and lower surfaces and U-S. through the butts of knitting needle actuating Cljacks pass construction comprises a first cam [58] Field of Search ..66/8, 38, 25, 57, 40, 42 means defining an upper Surface of the cam track and a second cam means defining the lower surface of the [56] References cued cam track. Said second cam means includes a tuck UNITED STATES PATENTS cam and an up-throw cam located adjacent each 1 78 9 7/ 9 H 66,2 X other. The second cam means also includes a follower owie 2,756,574 7 1956 Shortland 66 57 x and means i g g i the fonwer adjust 2,968,170 1/1961 Wiesinger ..66/38 mg mmemem respmse 3 W f 3,030,785 4/1962 Lunak 66 57 x 1 of the luck Moreover. means 18 provlded 3,387,466 6/1968 Beckenstein ..66/57 X for simultaneously adjusting the position of the up- 3,405,542 10/1968 Beckenstein ..66/40 X throw cam and the stitch cam relative to the tuck cam. 3,449,928 6/1969 Schmidt et al..... 66/57X 3,520,153 7/1970 Rothe ..66/57 4 Claims, 8 Drawing Figures I I l F 1 a /6 T /l g 1 26 e e e e W v 36 46' O /5 440 3 442) 32 54 I 30 31 a g e L O 1 2a 0 25 PATENTEDJAN 9197s 3.709.004

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FIGS

l Cl 2 aw? M 5 5 8 5 M w M n l //V VE/V TOR HORST PA 5pm? 0 w W QM ATTORNEYS CAM BOX FOR KNITTING MACHINE The present invention relates to a cam box construction, and particularly to a cam box construction for a circular knitting machine.

A cam box for a circular knitting machine comprises a plurality of cams which define a cam track through which butts of either a knitting needle or a needle-moving jack passes. The cams control the vertical movement of the needle or needle-moving jack as the butts pass through the cam track. By positioning the cams in a desired relationship, the movement of the needle or needle-moving jack can thereby be controlled. Two basic problems have plagued the designer of knitting machine cam box constructions. These basically are in the area of providing a simple reliable means of adjusting the cams so as to provide a smooth even movement of the butts in adjusted positions and, secondly, the elimination of areas in the cam track where the butts are liable to be broken or otherwise damaged by striking a cam surface with a forceful impact.

The present invention is directed to a cam box construction in which the cam track through which the butts pass is a smooth path and, in a general sense, has radii at every point where the butts change direction or elevation in order to minimize the possibility of damage to the butts or breaking of the butts.

The cam box construction of the present invention includes a plurality of cams which define a cam track through which the butts pass. The cams include a tuck cam which is adjustable between knit and non-knit positions. A follower cam is associated with the tuck cam and moves upon movement of the tuck cam and directs the butts onto the tuck cam in a smooth manner in all positions of the tuck cam. Also, the the cam track is defined by a stitch cam and an up-throw cam. The stitch cam and up-throw cam are adjustable as a unit, and the stitch cam defines not only a portion of the cam track with the up-throw cam, but also a portion of the cam track with the tuck cam. The simultaneous adjustment of the stitch cam and up-throw cam and their relationship with the other cams also minimizes th possibility of butt breakage.

Another feature of the present invention is the fact that the up-throw cam isremovable for needle jack replacement or cleaning of the feeder station and the up-throw cam and stitch cam have cooperating cam portions which accurately and precisely position the up-throw cam relative to the stitch cam upon re-assembly of the up-throw cam with the stitch cam. These various structural features of the cam box construction providean improved cam box having a minimum possibility of breakage of the butts due to the butts striking a camsurface with a forceful impact and, yet, provide for suitable adjustment of the cams.

Accordingly, the principal object of the present invention is the provision of a new and improved cam box construction for a knitting machine and which defines a cam track through which needle-moving butts pass, and which cam track provides an extremely smooth path so as to minimize the possibility of butt breakage.

A further object of the present invention is the provision of a new and improved cam box construction which defines a cam track through which the butts of the needle-moving jacks pass, and which cam track is defined in part by a tuck cam which is adjustable between tucking and knitting positions so as to control the movement of the needle-moving jack, and a follower cam is associated with the tuck cam and is mounted for movement with the tuck cam so as to provide a smooth passage of the butts onto the tuck cam at all positions thereof.

Another object of the present invention is the provision of a new and improved knitting machine cam box construction, as noted in the next preceding paragraph, wherein the follower cam is mounted for pivotal movement and is spring biased against the tuck can and has an arcuate end portion which fits the adjacent end portion of the tuck cam.

A still further object of the present invention is the provision of a new and improved knitting machine cam box construction defining a cam track having an upper and a lower surface, and wherein a plurality of separate cams define the lower surface of the cam track and one of the plurality of separate cams is removable for needle jack replacement or cleaning of the feeder station, and wherein the cam which defines the upper surface of the cam track has a cooperable portion with the removable can so as to position the removable cam when reassembled in the cam box construction in the proper location.

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description of a preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification and in which:

FIG. 1 is a somewhat schematic elevational view of the cam box constructions at two adjacent feeder locations in a knitting machine, and which cam box constructions embody the present invention;

FIG. 2 is a somewhat schematic elevational view illustrating a cam box construction of the prior art;

FIG. 3 is a sectional view of the cam box construction shown in FIG. 1, taken approximately along the line 33 thereof;

FIG. 4 is a fragmentary sectional view similar to that of FIG. 3 but illustrating portions of the cam box removed;

FIG. 5 is a sectional view of the cam box construction illustrated in FIG. 1, taken approximately along section line 5-5 thereof;

FIG. 6 is a sectional view of the cam box construction taken approximately along the line 66 of FIG. 7;

FIG. 7 is a view of the cam box construction of FIG. 6, taken approximately along the section line 7-7 of FIG. 6; and

FIG. 8 is a sectional view taken approximately along the line 8-8 of FIG. 7.

The present invention provides an improved cam box construction for a knitting machine, and particularly a circular knitting machine having a series of cam boxes located at adjacent feeder stations' and which define cam tracks through which knitting needle butts or the butts of needle-moving jacks move in order to effect the movement of the knitting needle as it traverses the respective feeder stations. The cam box construction of the present invention provides an extremely smooth path of movement for the butts as they move through the cam track, and also provides for ready and easy adjustment of the cams.

jacent cam box constructions, generally designated and 11. The cam box constructions 10, 11 are basically identical in design and only one of which will be described hereinbelow. These cam box constructions are located adjacent each other at different feeder locations around the perimeter of a circular knitting machine and control the knitting needle movement. The cam box constructions define cam tracks, generally designated 14 and 15, respectively. As shown representatively in FIG. 1, a knitting needle 16 has a butt 17 thereon which moves through thecam track 14. A needle-raising. jack 18 is pivotally attached at 19 to the knitting needle 16 for a purpose to be described hereinbelow. The jack 18 has a butt 20 thereon which moves through the cam track 15.

The needle-moving jack 18 is pivotally attached at 19 to the knitting needle so that the jack 18 may be pivoted in a direction so that the butt 20 can either selectively enter the cam track or not enter the cam track 15 at any given feeder station. The mechanism for pivoting the needle-actuating jack 18 so thatthe butt thereof selectively enters the cam track 15 or not is disclosed in detail in Paepke application Ser. No. 824,227, filed May 13, 1969, assigned to the assignee of the present invention, and reference may be made thereto fora detailed description thereof. Also, there is a detailed description of the entire knitting machine in said application and the entire disclosure of that application is incorporated herein by reference.

Since the cam'box constructions. 10, 11 are identical inconstruction, only the cam box construction 11 will be described in. detail and similar reference numerals will be used to designate similarparts-of the, cam box construction 10.The upper cam track 14 of the cam box construction 11 is defined by a pair of cams, designated 22 and 24..It should be noted that the cam track 14 includes a wide portion, designated by the arrow 26, so as to provide for movement of the butt 17 on the knitting needle 16 vertically in the event that the needle is raised by the needle-moving jack 18, as will be described hereinbelow. The cams 22 and 24 are secured by suitable fasteners to a support orframe of the knitting machine. i

The cam track 15, is defined by a plurality of cams 26,- 28, 30, 32 and 34, and also cam 24.As the butt 20 of the needle-moving jack enters the cam track 15, it first engages the cam 28 which has a cam surface 36. The cam surface 36 is located directly opposite a cam surface 38on a base portion of the cam 24. As the butt 20 moves along the cam surface and leaves it, it engages a cam surface 40 of the cam 30. The butt 20 of the selector jack 18 then engages a cam surface 42 of the cam 32, and then engages a cam surface 44 of the cam 34. The cam 26 has a cam surface 46 which isv located above and opposite -a part of the cam surface 40 of the cam 30,.as well as cam surfaces 42 and 44 of the cams 32 and 34, respectively.

The cam 32 is known as a tuck cam and is adjustable between various positions in order to control the raising movement of the needle-moving jack 18. The tuck cam 32 is illustrated in feeder station 10 in'one posi-. tion,:namely, the tuck position, and is illustrated in feeder station 11 in its knit position. The mechanism for moving the tuck cam 32 between its positions will be described hereinbelow, and the operation of the knitting needle 16 when the cam 32 is inthese positions is known.

The cam 26 is known as the stitch cam and controls the downward movement of the knitting needle. The

cam 34 which cooperates with the stitch cam to define an end portion of the cam track 15 as the needle moves out of the cam box 11 is also adjustable. The cam 34 is termed an up-throw cam, since it controls the upward movement of the needle as the needle leaves the feeding station. The cams 26 and 34 are also adjustable for well-known purposes and are shown in the feeder station 10 in an upper position, while in the feeder station 1 l they are shown in a lower adjusted position.

As noted hereinabove, the stitch cam 26 and the upthrow cam 34 are adjustable simultaneously so that the terminal portion of the cam track 15 in a feeder station is vertically movable or adjustable as a unit relative to:

the tuck cam 32. FIG. 3 specifically illustrates the mechanism for adjusting the stitch cam 26' and the upthrow cam 34. An illustrated in FIG; 3, the stitch cam 26 is secured by a threaded fastener or screw 50 to a support or block member 52. The block member 52 has a bar 53 associated with it which is received in an inclined slot 54 in the end of a rod member 55. The member 55 is supported for axial orlongitudinal movement by the frame of the knitting machine 56. It should be apparent that longitudinal movement of the member 55 will cause a camming action to occur between the slot 54 and the bar 53. This camming movement will resultin the bar 53 being raised or lowered. As shown in FIG. 3, the bar 53 is in its lowermost position and movementof the member 55 toward the right will effect raising of the bar 53 and the mechanism attached thereto, namely, the stitch cam 26.

The axial movement of the member 55 is effected by a mechanism, generally designated 60 and associated with the end of the member 55 opposite the end having the slot 54. The mechanism 60 includes a threaded member 61 which is threaded into the end of the member 55 opposite the end having the slot 54. A pin member 62 extends through the member 61 and through a plug member 63. The plug member 63 has an Allen wrench opening 64 in the end thereof. Rotation of the plug member 63 by use of an Allen wrench will effect rotation of the member 61 through the pin connection 62 and thereby effect the axial movement of the member 55. The member 63 is fixed against any axial movement by a suitable arrangement of washers and snap rings, which are generally designated 65. From the above, it should be apparent that rotation of the member 63 by use of an Allen wrench will effect axial movement of the member 55and which, in turn, will effect raising or lowering movement of the stitch cam 26 and 34.

The member 52, to which the stitch cam 26 is attached, has a portion'of a generally U-shaped projecting downwardly therefrom and generally designated 66. The U-shaped portion 66 defines an opening 67 between the legs of the U. The opening 67 is adapted to receive a tang portion or projection 68 of a support 69 for the up-throw cam 34. This projection forms one leg of a U-shaped portion 660 .of the support 69. The upthrow cam 34 is secured to the support 69 by a suitable threaded fastener 70 and positioning pins 71. The supleg of the U-shaped member 66.

Accordingly, upon vertical movement of the stitch cam 26, the up-throw cam 34 will likewise be adjustable vertically due to the cooperating interdigitated U- shaped members 66, 66a described above.

It should also be apparent from the description hereinabove that the cooperating U-shaped portions 66 and 66a associated with the stitch cam 26 and the upthrow cam 34 are removable with respect to each other so that the up-throw cam 34 may be slid or removed from the stitch cam 26, as is illustrated in FIG. 4. The removal of the up-throw cam 34 in this manner may be effected for purposes of needle jack replacement or for cleaning the feeder station, as is well known.

When the up-throw cam is removed, any needle jacks 18 which are located in the portion of the cam track 15 defined by the up-throw cam 34 would fall by gravity. This, of course, adds to the problem of accurately repositioning the u'p-throw cam 34 in the feeder station. The cooperating U-shaped portions 66, 66a associated with the stitch cam 26 and up-throw cam 34 readily solve the repositioning problems. When it is desired to reposition the up-throw cam 34 in the cam box, it is necessary only to move the up-throw cam 34 and its support 69 into position so that the butts 20 of the needle-raising jacks 18 engage the cam surface 44 thereof. A raising of the up-throw cam will result in raising of the jacks 18, and then inward movement of the up-throw cam 34 to engage the portion 68 in the opening 67 of the U-shaped portion 66 associated with the stitch cam results in accurate repositioning of the cam 34. The cooperative effect of the interdigitated portions therefor is to position the up-throw cam 34 properly with respect to the stitch cam 26 upon repositioning of the up-throw cam in the cam box.

As noted hereinabove, the tuck cam 32 is adjustable between two positions, shown respectively in knitting station and knitting station 11. The tuck cam 32, when in the position shown in FIG. 1, allows the needle-moving jacks 18 to move through the knitting station 10 without effecting at raising motion of the knitting needle-moving jack 18, thereby the knitting needle 16 does not knit but rather tucks at station 10. In station 11, the tuck cam 32 is adjusted for effecting knitting by the knitting needle and the position of the tuck cam is such that the butt 20 will move up the cam surface 42 thereof to effect the raising of the needleraising jack 18 which, in turn, effects a raising of the needle 16 to effect knitting at station 11. These operations and the cooperation of the needle and needleraising jack are described in detail in the afore-mentioned Paepke application.

The tuck cam 32 may be moved between its two positions and is supported for movement between its positions, as illustrated in FIG. 5. The tuck cam 32 has a shaft or pin portion. 80 extending therefrom and which is supported for rotation in a passage 81 of a support member 82. The end of the pin or shaft 80 is received in a bore 83 of a member 84. The member 84 has set screws 85 threaded therein and which engage the shaft member 80. From this construction it should be apparent that rotation of the member 84 will effect rotation of the tuck cam 32 about the axis of the pin 80.

The member 84 is rotatable to effect the rotatable movement or positioning of the tuck cam 32. To this end, the member 84 has a pin member 86 which projects transverse to the axis of rotation of the member 84. A cap member 88 extends over the end of the member 84 and is biased by a spring 89 outwardly thereof. The cap member 88 has slots 88a therein (see FIG. 7) which are adapted to be positioned so that the pin 86 may be received therein. The outer end of the cap member 88 has a slot 90 for the receipt of a screw driver therein.

Accordingly, positioning a screw driver in the slot 90 and forcing the cap member 88 inwardly into telescoping relationship with the member 84 against the bias of the spring 89 results in the opposite ends of the pin 86 being received in the slots 88a in the cap member 88. Once the pin 86 is received in the slots 88a of the cap member 88, turning of the screw driver will result in turning of the pin 86. Rotation of the pin 86 causes rotation of the member 84 and of the shaft 80 so as to effect rotation of the tuck cam 32 between its positions. In this manner, the position of the tuck cam can be adjusted. r

In order to provide for smooth movement of the butt 20 onto the tuck cam, regardless of the position of the tuck cam, the follower cam 30 is provided. The follower cam 30 will change its position in response to movement of the tuck cam 32. The follower cam 30, as illustrated in FIG. 6, is supported on a pin member of shaft member 100. The shaft member has an end portion 101 thereon which is received in a slot 102 in a U- shaped member 103, best shown in FIG. 8. Themember 103 is clamped into engagement with the member 101 by a screw 104. A spring 105 cooperates with the member I03 and urges the member 103 upwardly in a vertical direction, as viewed in FIG. 8. This upward or vertical movement in FIG. 8 urges rotation of the cam 30 in a counterclockwise direction, as viewed in FIG. 1, with the result being that the follower cam 30 is biased into engagement with the tuck cam.

It should be apparent that the follower cam 30 has a projecting end portion between which engages the base portion of the tuck cam 32 and against which the follower cam is biased. This end portion is shaped so that a smooth movement of the butts onto the tuck cam 32 occurs. Movement of the tuck cam 32, of course, as described above, will effect vertical pivoting movement of the follower cam 30. The movement of the follower cam and end portion design thereof results in a smooth easy movement of the butt 20 onto the tuck cam regardless of the position of the tuck cam 32.

It should be apparent from the description hereinabove that the cam box construction of the present invention provides an extremely smooth path for the movement of the butt 20 through the cam track. The provision of the follower cam 30 eliminates any rough movement or abrupt change in direction of the butt 2t) and also minimizes the possibility of breakage of the butt 26.

Moreover, as noted hereinabove, the stitch cam 26 extends over the tuck cam and the surface 46 thereof is disposed opposite to the cam surfaces 40, 42 and 44 of the follower cam 30, tuck cam 32, and up-throw cam 34, respectively. Adjustment of the cam 26 simultaneously with the adjustment of the up-throw cam 34 aids in providing a smooth even movement of the butt 20 removable type and the stitch cam 121 and up-throw I cam 122 are adjustable relative to the tuck cam 120. As a result, when the stitch cam 121 is in its solid line position, as shown in FIG. 2, the butt of a needle-moving jack will ,move out of the cam track 123 and engage with a forceful impactat point 124 with the surface of the stitch cam 121. If the stitch cam is moved vertically higher, than the solid line position, such as to the dotted line position shown in FIG. 2, the point 124 switches to point 125 and the uncontrolled movement of the butt 20 is even greater. This forceful striking of the stitch cam 121, common in the prior art, results in breaking of the butts from the needle-moving jacks, and the present invention is designed in an effort to solve this problem.

By the provision of the stitch cam 26 cooperating not only with the up-throw cam 34 but also with the tuck cam 32 to define the portion of the cam path above the tuck cam; as well as above the up-throw cam, such points as 124 and 125 are eliminated. Moreover, the follower cam 40 facilitates the entry of the butts onto the tuck cam and provides for an extremely smooth passage of the butts through the knitting stations.

Accordingly, it should be apparent that applicant has provided .a highly improved knitting cam box construction having a cam track which is defined by upper and lower surfaces. The upper surface is defined by sur faces 38- and 46 of the earns 24 and 26, and the lower surface is defined by surfaces 36, 40 and 42, 44 of cams 28, 30., 32 and 34,.respectively. The cams 28, 30, 32 and34 may therefore be defined as a plurality of cams which define the lower surface of the cam track 15, and the cams 24 and 26 may be defined as a plurality of cams defining the upper cam surface of the cam track 15. These terms are used in the claims which follow and it is intended hereby to cover all modifications and adaptations of the present invention which fall within the scope of those claims.

Having described my invention, 1 claim:

1. A knitting machine cam box construction defining a cam track having upper and lower surfaces and through which needle-actuating butts move, said construction comprising first cam means for defining the upper surface of the cam track and second cam means for defining the lower surface of the cam track, said second cam means comprising a plurality of separate cams, one of which comprises a tuck cam which is adjustable to vary the lower surface of the cam track so as to vary knitting needle movement thereby and another of which comprises a follower. camvfor controlling the butts prior to the engagement thereof with the tuck cam, said tuck cam having a surface engageable with the needle-actuating butts and which surface has an entry portion which initially engages the needle-actuating butts as they pass thereover, said follower cam having a surface engageable with the needle-actuating butts and which surface has an exit portion from which the butts pass off said follower cam, means mounting said tuck cam for pivoting movement about a first axis between tuck and knit positions, means mounting said follower cam for adjusting pivoting movement about a second axis below said first axis and parallel therewith with and in response to adjusting movement of said tuck cam, said follower cam extending upwardly from said second axis and terminating adjacent said second axis, said exit surface portion of said follower cam having a surface for guiding the needle-actuating butts onto the entry surface portion of the tuck cam when in both of its positions, and spring means biasing said follower cam into engagement with said tuck cam to maintain said exit surface portion thereof immediately adjacent said entry surface portion of said follower cam.

2. A knitting machine cam box construction defining a cam track having upper and lower surfaces and through which the needle-actuating butts move, said construction comprising first cam means defining the upper surface of the cam track and second cam means defining the lower surface of the cam track, said second cam means including a tuck cam and an up-throw cam located adjacent each other, said first cam means including a stitch cam located above said tuck cam and said up-throw cam, means mounting said tuck cam'for movement between a tuck position and a knitting position, means interconnecting said up-throw cam and said stitch cam, and means for simultaneously adjusting the position of the up-throw cam and the stitch cam relative to said tuck cam, said means interconnecting said up-throw cam and stitch cam including cooperable slidably removable portions connected with said upthrow cam and said stitch cam respectively so that said up-throw cam is radially removable from said stitch cam by relative radial sliding movement of said cooperable portions, said portions having guide surfaces which engage to guide and position said up-throw cam on reassembly and which interconnect said upthrow cam for simultaneous adjustment of said up throw cam and said stitch cam after assembly.

3. A knitting machine cam box construction as defined in claim 2 wherein said slidably removable portions comprises tang portions of U-shaped structures connected with said up-throw cam and said stitch cam, respectively.

4. A knitting machine cambox construction for a circular knitting machine having a needle-carrying cylinder rotatable about a vertical axis and which construction defines a cam track having an upper and a lower surface and through which butts for moving needles axially of the cylinder are conveyed, said construction comprising first cam means defining the upper surface of the cam track and second cam means defining the lower surface of the cam track, said second cam means defining a substantially continuous guide surface for said butts,,said continuous guide surface having a butt-raising surface portion directly engageable with the butts to positively raise same relative to the needle simultaneously adjusting the position of said up-throw cam and said stitch cam axially of the needle cylinder and relative to said tuck cam so that said butt-lowering cam track and said spaced surface portions are simultaneously adjusted. 

1. A knitting machine cam box construction defining a cam track having upper and lower surfaces and through which needleactuating butts move, said construction comprising first cam means For defining the upper surface of the cam track and second cam means for defining the lower surface of the cam track, said second cam means comprising a plurality of separate cams, one of which comprises a tuck cam which is adjustable to vary the lower surface of the cam track so as to vary knitting needle movement thereby and another of which comprises a follower cam for controlling the butts prior to the engagement thereof with the tuck cam, said tuck cam having a surface engageable with the needle-actuating butts and which surface has an entry portion which initially engages the needle-actuating butts as they pass thereover, said follower cam having a surface engageable with the needle-actuating butts and which surface has an exit portion from which the butts pass off said follower cam, means mounting said tuck cam for pivoting movement about a first axis between tuck and knit positions, means mounting said follower cam for adjusting pivoting movement about a second axis below said first axis and parallel therewith with and in response to adjusting movement of said tuck cam, said follower cam extending upwardly from said second axis and terminating adjacent said second axis, said exit surface portion of said follower cam having a surface for guiding the needle-actuating butts onto the entry surface portion of the tuck cam when in both of its positions, and spring means biasing said follower cam into engagement with said tuck cam to maintain said exit surface portion thereof immediately adjacent said entry surface portion of said follower cam.
 2. A knitting machine cam box construction defining a cam track having upper and lower surfaces and through which the needle-actuating butts move, said construction comprising first cam means defining the upper surface of the cam track and second cam means defining the lower surface of the cam track, said second cam means including a tuck cam and an up-throw cam located adjacent each other, said first cam means including a stitch cam located above said tuck cam and said up-throw cam, means mounting said tuck cam for movement between a tuck position and a knitting position, means interconnecting said up-throw cam and said stitch cam, and means for simultaneously adjusting the position of the up-throw cam and the stitch cam relative to said tuck cam, said means interconnecting said up-throw cam and stitch cam including cooperable slidably removable portions connected with said up-throw cam and said stitch cam respectively so that said up-throw cam is radially removable from said stitch cam by relative radial sliding movement of said cooperable portions, said portions having guide surfaces which engage to guide and position said up-throw cam on reassembly and which interconnect said up-throw cam for simultaneous adjustment of said up-throw cam and said stitch cam after assembly.
 3. A knitting machine cam box construction as defined in claim 2 wherein said slidably removable portions comprises tang portions of U-shaped structures connected with said up-throw cam and said stitch cam, respectively.
 4. A knitting machine cam box construction for a circular knitting machine having a needle-carrying cylinder rotatable about a vertical axis and which construction defines a cam track having an upper and a lower surface and through which butts for moving needles axially of the cylinder are conveyed, said construction comprising first cam means defining the upper surface of the cam track and second cam means defining the lower surface of the cam track, said second cam means defining a substantially continuous guide surface for said butts, said continuous guide surface having a butt-raising surface portion directly engageable with the butts to positively raise same relative to the needle cylinder, said second cam means including a tuck cam and an up-throw cam located adjacent each other and having surfaces forming a portion of said continuous guide surface, means mounting said tuck cam for movement between a tuck position and a knitting position, said first cam means including a stitch cam located above said up-throw cam, said stitch cam having a butt lowering surface portion engageable directly with the butts to positively lower same relative to the needle cylinder, said up-throw cam having a surface portion spaced from said butt-lowering surface portion of said stitch cam by a vertical distance substantially equal to the vertical dimension of said butt and defining a butt-lowering cam track portion, said stitch cam and said up-throw cam also having spaced surface portions for guiding the butts into said butt-lowering cam track portion as they leave said tuck cam and means for simultaneously adjusting the position of said up-throw cam and said stitch cam axially of the needle cylinder and relative to said tuck cam so that said butt-lowering cam track and said spaced surface portions are simultaneously adjusted. 